Private data includes data that an owner does not want to share with another party. Private data can include, for example, legally protected and/or personal data. As one example, private data can include an amount of money that a party is willing to pay to acquire an object. As a counter-example, private data can include a demanded amount of money, for which a person is willing to sell the object.
In some cases, two party's may wish to compare private data, without divulging the amount of value of the private data. Such a case is described as Yao's millionaires problem, which involves a comparison of private data. Yao's millionaire's problem includes two millionaires that would like to the amount of money that each one has without revealing the amount of money to each other. Although many solutions have been presented to resolve this problem, these solutions require significant computational efforts.